ИСТИНА

PROBA-3 is the next ESA mission in the PROBA line of small technology demonstration satellites. The main goal of PROBA-3 is in-orbit demonstration of formation flying techniques and technologies. The mission will consist of two spacecraft together forming a giant (150 m long) coronagraph called ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun). The bigger spacecraft will host the telescope, and the smaller spacecraft will carry the external occulter of the coronagraph. ASPIICS heralds the next generation of solar coronagraphs that will use formation flying to observe the inner corona in eclipse-like conditions for extended periods of time. The occulter spacecraft will also host the secondary payload, DARA (Davos Absolute RAdiometer), that will measure the total solar irradiance. PROBA-3 is planned to be launched in 2019. The scientific objectives of PROBA-3 will be discussed in the context of other future solar and heliospheric space missions (e.g. Solar Orbiter and Solar Probe Plus). A special attention will be paid to the interplay between space weather forecasting and optimal instrument operations. PROBA-3 will need space weather forecast to operate the ASPIICS coronagraph in an optimal way. The duty cycle of ASPIICS will allow observing only during limited periods of time, and the choice of these periods needs to be optimized to collect the data on as many coronal mass ejections (CMEs) as possible. This implies complex real-time science planning.